Higher order Lagrangians inspired by the Pais-Uhlenbeck oscillator and their cosmological applications

Gustavo Pulgar, JOEL FRANCISCO SAAVEDRA ALVEAR, Genly Leon, Yoelsy Leyva

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

We study higher derivative terms associated with scalar field cosmology. We consider a coupling between the scalar field and the geometry inspired by the Pais-Uhlenbeck oscillator, given by αthetasym;μφthetasym;νφ. We investigate the cosmological dynamics in a phase space. For α > 0, we provide conditions for the stability of de Sitter solutions. In this case the crossing of the phantom divide w= -1 occurs once; thereafter, the equation of state parameter remains under this line, asymptotically reaching towards the de Sitter solution from below. For α < 0, which is the portion of the parameter space where in addition to crossing the phantom divide, cyclic behavior is possible, we present regions in the parameter space where, according to Smilga's classification the ghost has benign or malicious behavior.

Original languageEnglish
Article number046
JournalJournal of Cosmology and Astroparticle Physics
Volume2015
Issue number5
DOIs
StatePublished - 26 May 2015

Keywords

  • dark energy theory
  • modified gravity

Fingerprint Dive into the research topics of 'Higher order Lagrangians inspired by the Pais-Uhlenbeck oscillator and their cosmological applications'. Together they form a unique fingerprint.

Cite this